mm/sharepool: Create global normal and dvpp mapping

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EORS


CVE: NA

--------------------------------

struct sp_mapping is used to manage the address space of a shared
pool. During the initialization of the shared pool, normal address
spaces are created to allocate the memory of the current shared pool.

Signed-off-by: Zhou Guanghui <zhouguanghui1@huawei.com>
Reviewed-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>